Midterm results following uncemented, modular, fully porous coated stem used in revision total hip arthroplasty: Comparison of two stem systems

Conversion total hip arthroplasty with a proximally modular, distal fixation reconstruction prosthesis following cephalomedullar nail failure

BACKGROUND

The goals of intertrochanteric hip fracture (IHF) treatment are stable fixation, early mobilisation and function restoration. If the attempt to reduce, stabilise and fracture healing utilising a femoral cephalomedullar nail (CMN) fails, options for subsequent attempts are limited.

PURPOSE

Evaluate the clinical and radiographic outcomes of conversion total hip arthroplasty (THA) using a modular stem following a CMN failure.

MATERIALS AND METHODS

We retrospectively reviewed a consecutive series of patients with an IHF between 2012 and 2014 to identify CMN patients that went on to the subsequent failure and conversion to THA utilising a modular femoral stem (MFS). In all cases, MP Reconstruction Prosthesis (Waldemar Link, Hamburg, Germany) was implanted. Primary clinical outcomes were assessed using Harris Hip Score (HSS) before conversion procedure, 3 months, 6 months and recent office visit post-conversion THA thereafter. The secondary outcome was to analyse intra and postoperative complications. Serial radiographs at each follow-up interval were assessed for clinical success or to confirm adverse events.

RESULTS

28 patients were included in the study; 17 were females. The average age was 72.7 years (SD ± 10.5); the average time from the index procedure to conversion THA was 12.6 months (SD ± 3.5). At baseline, average HHS was 42.1 (SD ± 3.6), improved to 80.7 (SD ± 5.1) at 3 months, 86.0 (SD ± 3.9) at 6-months which levelled off to 86.1 (SD ± 4.0) at final follow-up. There were 4 (14%) post-conversion complications: 2 dislocations, 1 superficial wound infection, 1 patient with symptomatic abductor deficiency. All 4 cases were conservatively treated successfully, the implants were retained, and the patients progressed without further issue.

CONCLUSIONS

MFSs allow to successfully treat failed CMN and adverse variations in femoral anatomy with a device that will permit simultaneous correction of leg length, offset and version to relieve pain, restore function and create a durable prosthetic to host composite.

Mid-term outcomes of titanium modular neck femoral stems in revision total hip arthroplasty

Background

Modular stems have been widely studied as they allow intraoperative adjustments (offset, anteversion, limb length) to better restore hip biomechanics. Many authors reported outcomes of revision total hip arthroplasty (THA) using modular stems with metaphyseal-diaphyseal junctions, however, little is known about modular neck femoral stems (MNFS) with metaphyseal-epiphyseal junctions. We therefore aimed to report outcomes and implant survival of a MNFS in a consecutive series of revision THA at a minimum follow-up of 5 years.

Methods

We reviewed a consecutive series of 28 revision THAs performed between February 2010 and March 2012 using an uncemented MNFS. The final study cohort included 25 patients living with their original components, at a mean follow-up of 68.4±7.4 months and aged 67.7±11.6 years at index operation.

Results

The Harris Hip Score (HHS) improved from 39.1±19.2 pre-operatively to 78.1±18.3 post-operatively, and the Postel Merle d'Aubigné score (PMA) improved from 9.8±3.0 pre-operatively to 14.8±2.8 post-operatively. The postoperative limb length discrepancy (LLD) was >10 mm in 18% of the hips. There were no significant differences of femoral offset and neck shaft angle (NSA) between operated and contralateral hips. Two hips (8.0%) showed new periprosthetic radiolucent lines. Periprosthetic fractures (PPF) occurred in 3 hips (12%). No subluxations, dislocations or implant breakages were reported. One revision (3.6%) was performed with retrieval of the revision stem for infection. The Kaplan-Meier (KM) survival at 5 years, using stem revision as endpoint, was 96.0%.

Conclusions

The Optimal^® MNFS provided a satisfactory survival and clinical outcomes at 5 years, with no noticeable adverse effects resulting from the additional modular junction.

Cementless, modular, distally fixed stem in hip revision arthroplasty: a single-center study of 132 consecutive hips

PURPOSE

The use of cementless, modular, distally fixed stem in hip revision arthroplasty has increased during the last decades. We aimed to analyze the early and late postoperative complications, re-operation rate, and survival rate of the MP stem operated at our county hospital with relatively limited caseload.

METHODS

In this retrospective study, we included 132 hips operated with MP stem between January 2007-2014. An independent observer reviewed patients' medical records in July 2015 (18-102 months postoperatively, median 52.5) to collect the following data: age, sex, American Society of Anesthesiologists (ASA) class, body mass index, indication of revision, type of operation, early and late complications, re-operation rate, and mortality during study period.

RESULTS

The commonest indication for MP stem operation was aseptic loosening (72%). We found early and late postoperative complications in 29% of cases. The most common complication was prosthetic dislocation (8%), followed by intra-operative peri-prosthetic fracture (5%). The commonest indication for MP re-operation was soft tissue revision for infection (7%) followed by closed reduction for prosthetic dislocation (6%). We found no correlation between the age, sex, ASA class, and type of operation and the re-operation risk. Only one prosthesis was extracted giving a survival rate for 99% for the study period.

CONCLUSION

This study showed good results of the MP prosthesis with reasonable complication and re-operation rates and negligible extraction rate, indicating the good performance of this implant even when used in the setting of a county hospital with limited caseload.